Don't see how it can't be the KDFW scenery install since it's the only scenery I installed after a complete reinstall of FS9 after uninstalling it and deleting all FS9 files. I flew a few flights after the install with no problem before installing KDFW.
As I've said, if your scenery.cfg ALREADY had a problem before installing KDFW, you wouldn't have noticed it, because FS9 simply skips an area with a problem or an error, but the Addon Manager module that comes with KDFW, needs to read the scenery.cfg too, and it *might* crash if the scenery.cfg has errors which FS9 might not care, but are errors anyway.
This, assuming the problem IS the scenery.cfg.
But even if it's not, fact that you had no problems before installing KDFW, doesn't automatically mean the problem is "caused" by KDFW. That's a common mistake users do, which seems logical, but it's not. For example, if you have an error like a missing or corrupted texture in one of you AI, which only appears at KDFW, you are mislead thinking the problem "must" be KDFW, when it's not.
Just to examples of things that might look like a KDFW problem, when they aren't. I'll give you a reply after seeing the scenery.cfg and in any case, even if it's not the scenery.cfg, there are other things to check.
complete reinstall of FS9 after uninstalling it and deleting all FS9 files
If you removed all the FS9 folder, it's still not a "complete" reinstall.
All your user preferences are not removed when uninstalling FS9, and there are files spread around in the %APPDATA% folder, the C:\ProgramData folder, the Documents folder, which are not removed by the uninstaller and being outside the main FS9 folder, are not so obvious they should be removed too, in order to have a really "complete" uninstall, which would remove any past problems you might have had with your previous install, which maybe prompted you to reinstall FS9 in the first place.